HONG KONG — One of the world’s most valuable start-ups got that way by using artificial intelligence to satisfy Chinese internet users’ voracious appetite for news and entertainment. Every day, its smartphone app feeds 120 million people personalized streams of buzzy news stories, videos of dogs frolicking in snow, GIFs of traffic mishaps and listicles such as “The World’s Ugliest Celebrities.”

Now the company is discovering the risks involved, under China’s censorship regime, in giving the people exactly what they want.

The makers of the popular news app Jinri Toutiao unveiled moves this week to allay rising concerns from the authorities. Last week, the Beijing bureau of China’s top internet regulator accused Toutiao of “spreading pornographic and vulgar information” and “causing a negative impact on public opinion online,” and it ordered that updates to several popular sections of the app be halted for 24 hours.

In response, the app’s parent company, Beijing Bytedance Technology, took down or temporarily suspended the accounts of more than 1,100 bloggers that it said had been publishing “low-quality content” on the app. It also replaced Toutiao’s “Society” section with a new section called “New Era,” which is heavy on state media coverage of government decisions.

The episode points to the fine line that Toutiao’s creators must walk.

Despite China’s famously strict censorship, online news is a big business there. More than 610 million people in the country gained access to some news on the internet in 2016, according to official statistics.

Toutiao, which says it uses complex algorithms to decide what its users see, combines China’s hunger for media content with its rising ambitions in artificial intelligence. Its daily user base of 120 million people is equivalent to more than one-third of the population of the United States.

Suan Lin, a 24-year-old private equity analyst in Shanghai, said that she normally has to search high and low online to find articles about the Chinese historical dramas she watches on television. But Toutiao delivers, she said.

“Once you’re on it,” she said, “you just can’t stop.”

In China, however, a strong position in media invites scrutiny from the government’s censorship apparatus. That scrutiny has become heightened over the past two years as the authorities have looked beyond the political to crack down on news it sees as degrading to society as a whole, which can include things as seemingly unsubversive as celebrity gossip.

In Toutiao’s case, one of the accounts that were suspended this week had posted a saucy video of a woman in a short skirt. It got 57,000 views. Another suspended account had recently put up a post titled “The World’s Ugliest Celebrities, Michael Jackson Is Ranked First, You Won’t Want to Eat After Reading This.”

“Once you have more people watching, then you want to be more cautious,” Wei-Ying Ma, who heads Toutiao’s artificial intelligence lab, told a conference in Beijing last month.

As Toutiao’s popularity has skyrocketed, Bytedance has become a darling of Silicon Valley investors such as Sequoia Capital. The company, which is currently valued at $20 billion, has been in talks with existing backers to raise new financing that would value the company at more than $30 billion, according to a person familiar with the discussions who spoke on the condition of anonymity because the details are not public.

That price tag would make Bytedance among the most valuable privately held technology companies in the world, not just in China. Airbnb is said to be valued at around $30 billion. SpaceX, the rocket maker founded by Elon Musk, is valued at $21 billion.

Bytedance has big plans for overseas expansion, too. It recently spent between $800 million and $1 billion to purchase Musical.ly, a video-based social network popular with teenagers in the United States and Europe. At the Beijing conference last month, a top Bytedance executive, Liu Zhen, said the company hoped to be earning half its revenue from outside China within the next five years.

Jinri Toutiao, whose name means “today’s headlines” in Chinese and is pronounced JING-er TOE-tee-yow, aggregates content from various sources and looks much like Facebook’s newsfeed. But instead of displaying articles and videos based on what your friends have shared, the app does so based on what you have previously read and watched on the app.

If you click on articles about iPhones, then Toutiao will feed you more tech coverage. After you watch a few cooking videos, the app will fetch you more clips of people wrapping dumplings and braising chicken’s feet.

This approach has helped Toutiao thrive amid China’s heavily controlled environment for social media. Instead of policing the sharing activity of tens of millions of users, the company needs only to calibrate and adjust its centralized recommendation software.

But it also needs to make sure the app’s content does not cross the lines of censors. That is a huge task, particularly given that the overwhelming majority of content on Toutiao is produced by individual bloggers, not professional news organizations or other institutions. Ms. Liu said at last month’s conference in Beijing that 90 percent of the app’s content comes from blogger accounts. Toutiao has around 1.2 million content-producing accounts in total.

According to Bytedance, every piece of content is automatically screened to check that it is acceptable before appearing on Toutiao. But once something has attracted more views, the system applies a more sophisticated screening algorithm. Certain material is also examined by humans as a final check.

Bytedance also takes more overt steps to stay on the right side of the authorities. Important updates from the government are sometimes pinned to the top of a user’s feed. That can lead to awkward juxtapositions — between, say, a state media write-up on President Xi Jinping’s recent decisions and a photo slide show on six women who are “so beautiful that rich businessmen immediately became attracted to them,” as the piece’s headline puts it.

Toutiao has come in for official rebuke before. Last June, the Beijing bureau of the Cyberspace Administration of China ordered around a dozen accounts on the app shut down, calling on Toutiao and other news portals to “actively promote socialist core values” and create a “healthy, uplifting environment for mainstream opinion” by eschewing dishy coverage of celebrity scandals.

In September, the website of the People’s Daily newspaper, the official mouthpiece of the Communist Party, published a series of opinion articles strongly criticizing A.I.-based news apps, including Toutiao, for spreading misinformation and superficial content.

An earlier version of this article misstated how Bytedance screens content uploaded to its Jinri Toutiao news app. All content gets screened by a basic computer algorithm. It is not the case that content is not screened if it is seen by only a handful of people. The incorrect information came from a comment by Wei-Ying Ma, head of Toutiao’s artificial intelligence lab, who told a Beijing conference last month that, “If there’s a video that one or two people watch, we don’t care.”